Spacecraft separation system for spinning vehicles and/or payloads



Nov. 22, 1966 s, s L ET AL 3,286,630

SPAGECRAFT SEPARATION SYSTEM FOR SPINNING VEHICLES AND/OR PAYLOADS FiledMay 4, 1965 5 Sheets-Sheet 1 FIG. 1c

INVENTORS SEYMOUR SALMIRS OTIS J. PARKER ORNEYS Nov. 22, 1966 s, $ALM|R$ET AL 3,286,630

SPACECRAFT SEPARATION SYSTEM FOR SPINNING VEHICLES AND/OR PAYLOADS FiledMay 4, 1965 5 Sheets-Sheet 2 INVENTORS SEYMOUR SALMIRS OTIS J. PARKER QC1 BY fld ATTORNEYS Nov. 22, 1966 SPACECRAFT SEPARATION SYSTEM FORSPINNING VEHICLES AND/OR PAYLOADS Filed May 4, 1965 S. SALMIRS ET AL 5Sheets-Sheet 5 FIG. 4

INVENTORS SEYMOUR SALMIRS OTIS J. PARKER ATTORNEYS handle.

United States Patent M SPACECRAFT SEPARATION SYSTEM FOR SPIN- NINGVEHICLES AND/ OR PAYLOADS Seymour Salmirs, Newport News, and Otis J.Parker, Chesapeake, Va., assignors to the United States of America asrepresented by the Administrator of the National Aeronautics and SpaceAdministration Filed May 4, 1965, Ser. No. 453,227 16 Claims. (Cl.10249) The invention described herein may be manufactured and used by orfor the Government of the United States of America for governmentalpurposes without the payment of any royalties thereon or therefor.

This invention relates to mechanism for separating a spacecraft, andmore particularly to a separation technique wherein the despin mechanismof one stage is utilized to cause separation of the stages and tumblingof one stage with respect to the other.

Various prior art techniques are available to perfect the separationbetween stages of a space vehicle. Among these prior art separationmechanisms are blowout diaphragms, Marmon bands, Marmon bands incombination with retrorockets or springs, shaped explosive charges andothers. Although many of these separation mechanisms are operative forthe purpose intended, they have many disadvantages particularly forcertain types of vehicle missions. For instance, when it is necessary toseparate the spacecraft, payload, or upper stage rocket (constitutingthe upper stage), from a lower stage and the upper stage must be stable,or it is necessary to sense or view from the aft end, or extension ofantenna or other devices from the aft end is required, many difficultiesoccur using these structures. Under these conditions, diaphragms causelarge disturbances and are comparatively heavy. Marmon bands andassociated hardware are complex and relatively heavy. Explosive chargesrequire extensive development for each configuration and are difficultto All of these separation systems require long time delays after thelower stage burnout in order to avoid possible collision afterseparation due to the lower stage out-gassing. This invention overcomesthe above-mentioned difliculties and will separate the upper stage fromthe lower stage with a minimum of delay utilizing a simple mechanicalsystem which is light in weight and easy to construct.

It is, therefore, an object of this invention to provide stageseparation mechanism wherein the relative movement (spin energy) betweenthe stages due to despin of one of the stages is utilized forseparation.

Another object of the invention is to provide vehicle stage separationmechanism wherein relative rotation between the stages upon separationis utilized to impart relative axial acceleration to the stages.

A further objectof the invention is to provide stage.

separation mechanism wherein the structure utilized to despin one of thestages is also used to tumble one of the stages out of the path of theseparated stage.

Still another object of the invention is to provide stage separationmechanism using rolling members to reduce 3,286,630 Patented Nov. 22,1966 tion will become more apparent upon reading the specificationin'conjunction with the accompanying drawings.

In the drawings:

FIGS. 1a, 1b and 1c are perspective views showing a stage separationsequence utilizing the invention mechanlsm;

FIG. 2 is a plan view of the vehicle stages, partially cut away toreveal elements of the separation mechanism;

FIG. 3 is a cross-sectional view taken along the section lines IIIIII ofFIG. 2;

FIG. 4 is a cross-sectional view taken along the section lines IVIV ofFIG. 2; and

FIG. 5 is an enlarged elevational view showing a portion of the vehicleraceway in an expanded position.

Basically, this invention relates to mechanism for joining andseparating stages of a space vehicle. Generally, the lower stage hasformed therein a raceway in the nature of a ramp. Associated with theraceways are arms which overlie a portion thereof. The upper stage orpayload has a channel formed about the lower portion thereof which mateswith the raceway structure. Arcuate recesses are formed in the channeland retaining brackets located at intervals thereabout and receive ballswhich nest in the arcuate recesses and roll on the raceways. When thestages are mated, they are positioned such that the balls are locatedunder the'arm structure,,thus preventing axial or longitudinalseparation. The stages are prevented from relative rotation by thedespin weights which have keys engaged in keyways formed in the stages.The weights are lashed in position by a cable. When it is desired toseparate the stages, a cable cutter severs the cable which loosens theweights allowing them to be flung from the spinning stage. The weightsare attached to one of the stages by wires and'this stage despun by theYo-yo technique. This causes one of the stages to overrun the other, theballs rolling on the raceways and thereby separating the stages.

Referring now more specifically to the details of the invention, thespacecraft separation system is designated generally by the referencenumeral 10 (FIG. 1).

Included in the spacecraft separation system 10 is a spacecraft or upperstage 12 having a housing 13. The base 14 (FIGS. 3 and 4) of the housingis thicker than the remainder of the housing .and offset inwardly.Formed in the outer face of the base is a channel 15. De tents 16 arepositioned at space intervals about the channel 15. The detents 16, of agenerally arcuate design, being adapted to receive steel balls, to beexplained more fully hereinafter. A base keyway 17 (FIG. 4) is formed inouter surface of the housing to receive the key of the despin weight, tobe explained subsequently. Threaded screw apertures 18 are located inthe base 14 adjacent the detents 16 to receive fasteners for securingthe retainer bracket now to be described.

The retainer bracket 25 is located at each of the detents and isgenerally L-s'haped in configuration. It has screw openings 27 in oneleg thereof which receive screws 30 for securing the bracket to thehousing base. The other leg of the retainer bracket projects under thebase of the housing and ha-s a pocket 26 formed therein which mates withthe detent 16 formed in the channel. Thus, the combined detent 16 andpocket 26 form a generally hemispherical recess to receive the rollableball, to be explained more fully hereinafter.

The lower stage is designated generally by the reference numeral 35.Formed in the lower stage is a series of raceways 36. .As shown in FIG.2, there are four raceways; however, it is to be understood that it iswithin the scope of the invention to have more or less as the situationmight demand. FIG. 5 shows an expanded view of the raceway andillustrates that it is generally in the nature of a ramp with a gradualslope a from one end to the other and designed to transmit uniformaccelerated axial motion. FIG. 3 also shows that the raceway is formedin a little over half the thickness of the lower stage casing and has anarcuate or rounded bottom which conforms generally to the configurationof the ball to be associated therewith. It is also clear from FIG. thatarms 37 are formed with the raceways and project over a portion thereof.The arms 37 cooperate with the balls to prevent movement along thelongitudinal axis until .despin occurs causing the upper stage tooverrun the lower stage. Lower stage keyways 38 are notched in the outerperiphery of the lower stage so as to be alined with the upper stagekeyways.

The raceway balls 45 are constructed of stainless steel and are highlypolished to eliminate excess friction. As is shown in FIG. 3, the balls45 rest on the bottom of the raceways 36 and nest in the [recess formedby the detents 16 and pockets 26, located in the upper stage base andretainer bracket respectively.

The despin mechanism consists of a release 50, release wire 53, weight54, anchor 60, anchor wire 61 and anchor weight 62. These are bestillustrated in FIG. 4, the release 50 being of the same type asdescribed and illustrated in detail in Patent No. 3,128,845. The anchor60 is of the same general design .as the release 50 but has the releaseopening blocked to prevent release of the weight. The weights have keys55 and 63 which engage the keyways 17 and 38 in the upper and lowerstages (FIGS. 2 and 4).

A lashing cable 70 surrounds the stages and engages grooves formed inthe weights 54 and 62. The lashing cable 70 is threaded through apyrotechnic or other form of cable cutter 75 which severs the cable andreleases the weights upon despin to be explained more fully in theoperation of the invention now to be described.

Operation The upper and lower stages are joined or assembled byorienting the stages to their [relative positions assumed uponseparation. The balls are positioned on the raceways 26, in the detents16 and the retainer brackets secured to the housing base by the threadedfasteners 30 the pockets thereof also engaging the balls. The stages arethen rotated until the balls 45 assume a position at the lowest portionof the raceway incline and under the arms 37. In viewing FIGS. 3 and 5simultaneously, it can be seen that the upper and lower stages arejoined and prevented from movement in the longitudinal direction as longas relative rotation between the stages is prevented.

Locking of the stages from relative rotative movement is accomplished bythe weights 54 and 62 which have the keys thereof 55 and 63 engaged inthe keyways of the upper and lower stages (FIG. 4). The weights aremaintained in position by the lashing cable 70. The

release and anchor wires 53 and 61 are attached to the respectiveweights and to the release 50 and anchor 60.

The space vehicle is launched in a conventional man ner, such as bybooster, and at a desired point in space spun up by spin rockets also ofconventional design (the detail of this structure not being shown). Whenit is desired to separate the stages the pyrotechnic cutter 75 isactuated severing the lashing cable 70. The pyrotechnic cutter may becontrolled remotely, by timer or by various other techniques known inthe art.

When the lashing cable 70 is severed, the spinning of the stages willcause the weights 54 and 62 to fly out from the vehicle as isillustrated in FIG. 1b. As the weights and cables move away from thelower stage, the momentum primarily of the lower stage is transferred tothese members according to the principle of the Yo-yo de-spin systemcausing the lower stage to rotate at a slower speed or despin. Since theweights are connected to the lower stage, they have little affect on theupper stage which continues to spin near the speed of initial release,the only coupling between stages being the friction of the balls.Consequently, the upper stage overruns the lower stage and the balls 45associated therewith are carried thereby travel up the raceways 47.

Once the balls 45 clear the end of the arms 37, it is apparent that theupper and lower stages are free to separate in the longitudinaldirection. Due to the weight of the upper stage, the balls may continueto ride on the raceway until they reach the upper extremity and ride offthe top of the arms 37 or may separate depending on factors such as spinrate, etc. Due to the incline of the raceways and the momentum of theupper stage, the upper and lower stages are accelerated in the axialdirection away from each other as the balls travel up the raceway.

Shortly after the stages separate, the release wire 53 and weight 54have reached a position whereby the weight is released and moves awayfrom the lower stage. The anchor weight, however, is permanently fixedto the lower stage and as it continues to spin causes the lower stage totumble out of the path of the upper stage. This action is believed to beapparent from viewing FIG. 1b. The spinning of the lower stage is ratherwell stabilized as long as both weights are attached; however, as shownin FIG. 10, when the one weight is released the spinning bodyimmediately becomes unbalanced. Furthermore, the lower stage is spun inthe opposite direction as the attached weight rewinds about the lowerstage. Thus, the lower stage is not only tumbled, but its pointingdirection :is stabilized away from the path of the upper stage.

From the above description, it is believed apparent that a stageseparation mechanism has been set forth which is of a simple, efiicientand reliable design. Obviously, there is but a small time lapse betweenthe time of actual separation and the time when the lower stage istumbled out of the path of the upper stage. Therefore, it is notnecessary to wait for the out-gassing of the lower stage before the aftend of the upper stage can be utilized for antenna erection or othersensing devices. If the upper stage has a rocket motor, it may beignited immediately without disturbing its direction of firing.Certainly, there is no large disturbance due to separation as might bethe case with a blowout diaphragm or other separation techniques. Theseparation mechanism consists of a minimum number of parts which arelight in weight and therefore well suited for space use. The design ofthe raceway not only facilitates separation of the stages but utilizesthe energy of the spinning upper stage to accelerate separation. Thesystem provides mechanism for eifectively separating the stages, as wellas for joining the stages during the launch phase. Thus, the stages areproperly joined and locked together until the despin phase withoutadditional fastening and support structure.

Since there are, obviously, many modifications and variations of thepresent invention possible in the light of the above teachings, it istherefore to be understood that within the scope of the appended claimsthe invention may be practiced otherwise than as specifically described.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. Space vehicle separation mechanism or the like for a spinning vehiclecomprising: an upper stage; a lower stage in juxtaposition to said upperstage; balls engaging said upper and lower stages for joining saidstages together; means for changing the relative speeds of rotationbetween the stages causing one stage to overrun the other; and means foraccelerating separation of the stages.

2. Space vehicle separation mechanism or the like for a spinning vehicleas in claim 1 wherein one of said stages has raceway means for saidballs to roll on and being arranged to increase axial acceleration ofone of said stages upon separation.

3'-. Space vehicle separation mechanism or the like for a spinningvehicle as in claim 2 wherein the lower stage has the raceway means.

4. Space vehicle separation mechanism or the like for a spinning vehicleas in claim 1 wherein said means for changing the relative speeds ofrotation between the stages is despin weights.

5. Space vehicle separation mechanism or the like for a spinning vehicleas in claim 1 wherein said lower stage has raceway means for said ballsto roll on and being formed to increase axial acceleration between saidstages; and means for changing the relative speed of rotation betweensaid stages being despin weights.

6. Space vehicle separation mechanism or the like for a spinning vehicleas in claim 1 wherein said lower stage has raceway means for said ballsto roll on and being formed to increase axial acceleration between said.stages; means for changing the relative speed of rotation between saidstages being despin weights; release means for at least one of saidweights whereby the stage attached thereto is tumbled out of the path ofthe other stage.

7. Space vehicle separation mechanism or the like for a spinning vehiclecomprising: an upper stage; a lower stage in juxtaposition to said upperstage; means for joining said stages together; despin weight means forchanging the relative speed of rotation between the stages caus ing onestage to overrun the other; and means for accelerating separation of thestages.

8. Space vehicle separation mechanism or the like for a spinning vehicleas in claim 7 wherein there is release means for at least one of saidweights; and means for retaining at least one of said weights wherebythe stage attached thereto is tumbled out of the path of the otherstage.

9. Space vehicle separation mechanism or the like for a spinning spacevehicle as in claim 7 wherein there is cable means for lashing saidweights to one of said stages prior to despin; and means for cuttingsaid cable to release said weights.

10. Space vehicle separation mechanism or the like for a spinningvehicle as in claim 7 wherein there are weights having keys engagingkeyways in said upper and lower stages prior to despin to preventrelative rotation between said stages.

11. Space vehicle stage separation mechanism or the like for a spinningvehicle comprising: an upper stage having a base; a channel formed insaid base; a lower stage; raceways formed in said lower stage and beinglocated adjacent said upper stage channel retainer brackets fixed tosaid channel at spaced intervals thereabout; arcuate recesses formed insaid channel and said retainer brackets; balls nesting in said arcuaterecesses and on said raceways; and means for rotating said stagesrelative to each other causing said balls to roll on said raceways toseparate said stages.

12. Space vehicle separation mechanism or the like as in claim 11wherein said raceways have formed therewith an arm overlying a portionthereof and said balls to prevent separation of said stages prior torelative rotation therebetween.

13. Space vehicle separation mechanism or the like as in claim 11wherein said raceways are formed in the nature of a ramp to impart axialacceleration between said stages upon relative rotation and separation.

14. Space vehicle separation mechanism or the like as in claim 11wherein said raceways have formed therewith an arm overlying a portionthereof and said balls to prevent separation of said stages prior torelative rotation therebetween; said raceway being formed in the natureof a ramp to impart axial acceleration to said upper stage upon relativerotation and separation.

15. Space vehicle stage separation mechanism or the like comprising: anupper stage having a base; a channel formed in said base; a lower stage;raceways formed in said lower stage and being located adjacent saidupper stage channel; retainer brackets fixed to said channel at spacedintervals thereabout; arcuate recesses formed .in said channel and saidretainer brackets; balls nesting in said. arcuate recesses and on saidraceways; said racew-ays having formed therewith an arm overlying aportion thereof and said balls to prevent separation of said stagesprior to relative rotation therebetween; despin weight means attached tosaid lower stage to cause said upper stage to overrun and said balls tomove on said raceways; said raceways being formed in the nature of aramp to impart axial acceleration between said stages upon relativerotation and separation; release means for one of said despin weights;and means for retaining another of said despin weights whereby the lowerstage is tumbled out of the path of the upper stage and spin stabilizedin another direction.

16. Space vehicle separation mechanism or the like as in claim 15wherein said weights have keys engaging keyways formed in said upper andlower stages to prevent relative rotation therebetween prior to despin;cable means for lashing said weights to said space vehicle; and meansfor cutting said cable to release said weights to initiate despin andseparation.

References Cited by the Examiner UNITED STATES PATENTS 2,775,163 12/1956Vegren 89--1.7 2,871,762 2/1959 Schmued 891.7 2,968,245 1/ 1961 Suttonet al 102--49 3,128,845 4/ 1964 Parker 102-49 References Cited by theApplicant UNITED STATES PATENTS 1,488,182 3/ 1924 Whelton. 2,654,320 10/1953 Schmid. 2,932,252 4/ 1960 Korn. 2,967,482 1/1961 Toomey. 3,004,48910/1961 Griffith et a1. 3,023,703 3/ 1962 Beatty. 3,088,403 5/ 1963Bartling et a1. 3,109,608 11/1963 Boehm et a1. 3,110,260 11/1963 Slomka.

3,111,900. 11/1963 Fitton et al.

BENJAMIN A. BORCHELT, Primary Examiner.

V. R. PENDEGRASS, Assistawt Examiner,

1. SPACE VEHICLE SEPARATION MECHANISM OR THE LIKE FOR A SPINNING VEHICLECOMPRISING: AN UPPER STAGE; A LOWER STAGE IN JUXTAPOSITION TO SAID UPPERSTAGE; BALLS ENGAGING SAID UPPER AND LOWER STAGES FOR JOINING SAIDSTAGES TOGETHER; MEANS FOR CHANGING THE RELATIVE SPEEDS OF ROTATIONBETWEEN THE STAGES CAUSING ONE STAGE TO OVERRUN THE OTHER; AND MEANS FORACCELERATING SEPARATION OF THE STAGES.